hogue



Dec. 4, 1956 w HOGUE Re. 24,252

HYDRAULIC MOTORS Original Filed May-31, 1952 2 Sheets-Sheet 1 INVENTOR. Ephra/m W Hogue "war-AW A ftor'neg Dec. 4, 1956 E. w. HOGUE Re. 24,252

HYDRAULIC MOTORS Original Filed May 51, 1952 2 Sheets-Sheet 2 Bloc/b8 Blades 6, 7, czc.

IkVVENTOR. 1'1 9 7 E hraim H4 Hogue After-neg angle of rotation depends United States Patent OflFice.

Re. 24,252 Reissued Dec. 4, 1956 HYDRAULIC MOTORS Ephraim W. Hague, Bethesda, Md.

Original .No. 2,730,076, dated January 10, 1956, Serial No. 290,870, 'May 31, 1952. Application for reissue August 3, 1956, Serial No. 602,091

8 Claims. (Cl. 12156) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This invention relates to hydraulic motors.

Broadly, the invention comprehends a hydraulic-motor of simple, compact and durable structure including but few parts which may be easily manufactured and quickly assembled. The invention further :comprehends a hydraulic motor which is light in weight, simple in principle, as well as in structure, and yet capable of delivering large torques. A motor which may be operated on a small volume of fluid and which is capable of running smoothly at high speeds with little, if, any, vibrationf It has no slippage and it will deliver a substantially constant torque when working under difierential. 1 r

The motor has-the advantage of a positive control by controlling the flow of fluid therethrough. ,Tna; is, the only on the volume of'fiuid passed through the motor-and as a result, the motor may it's-exhaust. It maybe reversed by simply reversing the fluidflow to it, and it may also beusedasapump. j

An object of the invention is to provide a relatively small motor, light .in weight, mechanically rugged and highly eflicient in performance.

Another object of the -Fig. 1- is a vertical sectional view partly broken away;

Fig. 2 is across sectional Fig. I;

Fig. 3 is a perspective view'partly broken away;

Fig. 4 is'a' perspective' view illustrating a detail of the fluid system and itsrelation to the reciprocal blades;

Figures 5 and 6 are diagrams of a hypothetical motor fromv which vised; and

a constant fluid pressure the motor illustrated in Figures 1+4- was de preferred because such 2, springs tend to equally distribute the force applied to the blade and thus avoid cocking and/or binding of the blade in the slot.

Spaced annular passages 26 and 28 comprising an inlet manifold and an outlet manifold respectively are arranged in the core of the stator in parallel relation to one another and in concentric relation to the stator. An intake passage 30 communicates with the annular passage 26 and leads to an intake port 32 preferably arranged in the base '10, and radially disposed passages 34 each communicating with the annular passage 26 and terminate in flared inlet apertures or nozzles 36 having a width substantially commensurate tothat of the blades 20 and the nozzles discharging atthe perimeter of the stator, one immediately back of each blade. Correspondingly, an

' exhaust or a discharge passage 38 communicates with the Figure 7 is a diagram illustrating the pointof sym -j metry.

Referring to the drawings for more specific details of the lIlVCntlOll, indicates a base which may be fixedly secured in any desirable mammary The base supports a stator 12. As shown, the statoris a; cylindrical, body,

theperipher'y 14. and ends-=16 of which aremachin'edandi' polished (not indicated in drawing).

Equi spaced slots 18 arearranged in the peripl era l face 12 oflthe stator and blades reciprocal inthe slotshave theirouterfiedges rounded as indicated at 22, the purpose of which will hereinafter appear. urged radially outward by springs the blades and the bottoms of the slots. The springs The blades are 24 interposed between may be of any desired'type, however, leaf springs are i 1 ing awidth commensurate to that of 1 sealsbetween the stator 7 distance measured annular passage 28 and leads to a ranged in the base 10, and radially discharge port 40 ardisposed passages 42 each communicating with the annular passage 28 termi nozzles 44 each hava blade 20 and each of the stator, one immediately mate in outlet apertures or scavenger opening at the perimeter forward of each blade.

oppositely disposed annular slots 46 and 48 arranged in the ends 16 of the stator each receive a ring 50 seated on a ribbon spring 52 resting on the bottom of the slot. Preferably the rings 50 i i as small the overdiameteras-f possible taking into consideration all size of, the motor.

and the rotor. While a specific fluid seal has been described, it is to be other types may be'employed. However, the structure hereinabove described would offer the optimum of friction. t

A rotor indicated generally at 54 includes a' heavy ring 56, having an inner circumferential channel 58 of a width complementary-to that of the blades 20, and a flange 59 normal to one edge thereof and flapped against one end of the stator and bearing against the graphite bronze ring 50 in the annular slot'46 so as to inhibit seepage of fluid from the motor.

The channel 58 is so contoured as to provide in efifect a plurality of successive chambers 60 characterized in that they correspond to one another and present continuous sine curve surfaces receiving the free ends of the blades 20 with line contacts so as to reduce friction to a minimum, and further characterized in that the number of -chambers 60 thus provided exceed the number of blades 20 by one.

It is to be observed that when using the term chamber 60 to define the space between the lines of the stator with the rotor, the ratio of the length 8 of the f N where N is a whole number. As a result of this the blades will not occupy identical positions in the chambers. The

positions of the blades will be progressive, each blade.

the preceding one,

continuous sine and/or cosine curves and that since the along the perimeter of. the stator between the contact lines of the stator and the rotor conare made of graphite bronze. .They shouldbe'narr'ow in cross section and of The rings 50 function as fluid understood that stitutes a single chamber length designated L and corresponding. to Zrr radians, the position of a blade-inthechamber can be specified byits phase angle With respect to the origin of the curve. Thus it is clear that if a L fi the. blades will occupy N different phases atalltimes,

the: phase of each blade differingby an. angle. of

radians from that of'the adjacent blades. Thuseach. blade carries aproportion of the load depending upon. its-phase-and it can be shown-that the total force exerted by all blades (provided they, are equally spaced.) is constant, accordingly, the torque produced by the motor when working'under constantifluid pressure differential; isconstant.

Toxaid inunderstanding the. principle of operationof' the fluid motor, Figures and 6 and thefollowingdescription of the operation of-a hypothetical engine from which the rotary fluid motor-of Figures 1, 2; 3, and4 was derived is provided.

Figure 5 shows the cross-section of a hypothetical engine made up of two-blocks. A, and B'. A presses firmly against B and presents to it the regularly repeating smooth curved surface shown. A series of blades sliding in equally spaced slots in-B, and free to move up and .down, are pressed against the camlike surface ofYA by' spring tension. If now a fluid is forced into'ithe spaces-between A and B to theleft of eachbladewhile-it is allowed to leave the space to the right of each blade, A will be made to move to the-left, if B:is held stationary.

In order that it shall always remain impossible for fluid to flow directly from inlet to: outlet, these. being l o'-- cated. in B close to each blade, it is.necessary that-the distance between the contacts. of A- with B be shorter than the distance between the blades. S must be greater thanLinFigure 5.'

Further, in order that the'total forceturging .A-to the left be constant as 'A' moves (assuming'constant' fluidpressure differential) it can be seenthatth'e' total bladearea projecting above B must not vary. Whether'th'e total blade. area remains constant or notdep'en'ds upon the shape of the regularly repeating camlike surface in=block- A. If the rotary-fluid motor derived from the hypothetical one (in a manner to be described below) is notto' be restricted to an even number (divisible by 2)-of' blades, there is onlyone curve shape whichiwill maintain the total blade area-projecting above B-constant. This curve" is the sine orcosine curve. If thennumber .of blades in-the rotary engine is restricted to'anfevenkvalue, other-curves of 'a special class will maintain constant tot-a] active blade area. This class includes-the: sine or cosine curve=as-a special case. Because the sine. or cosine-curve does not restrict the blades to an even number and because-it .is the smoothest possible curve giving a minimum of ac celeration to the blades it-willbenchosen as the shape-of the regularly repeatingisurfaceinbloekAr- Using the term chamber. for the open space in A between the points of contac-tofA -with B, it can be seen that if the ratio of the distances between the blades, to one chamber length L is madewhere N is a whole number, the blades will not all occupy identical positions in the chambers. Their positions will be progressive, each bladebeing a distance L/N farther along in .its chamber than the preceding one in the manner of a vernierj' The 1st, 5th,- 9th and 13th etc. blades will occupy.identicalpositions in their respective. chambers; as will the 2nd,- 6th,- I0'th, 14th and so on.

' blades engaging A.

4'. If the camlike surface of A is a sine or cosine curve, the distance L between successive contact points of-A with B, corresponds to 211' radians. One chamber is then 21r radians long. The position of the blade in its chamber can be specified by its phase angle with respect to the origin of the curve. It can-beseen that if the blades will occupy N- different phases. at. all times, the phase of each blade differingby an angle of (2'1r+21'r/ N) radians from that of its neighbor. See Figure 5.

Figure 6 shows the generating-circle for the curve in Figure 5. Here are shown also the phase relations of the. blades by the vfour equally 'spacedipoi'nts onthepcircle. corresponding to the-N=,4-distinct phases. ofj-theaparticuw lar engine shown. around the generating circle is equivalent to sliding A along B in Figure 5. Itcan berseen from the -symmetry of the: circle and equally spaced'phase points that-- the total blade area, that .is':

blade width times (h1+h2:lha+h4.+h5+ etc.)

will be constantasA moves provided the numbcr'of be. constant whether N is-even or odd. This is true only for the circle as a generating figure, and hence only. for thesine or cosine cam curve. However, ifNis even,: corresponding to an, evennumberof bl'adesin the rotary motor, cam curves derived from generating curves .WhlCh have a point of symmetry will provide constant total. ac-

- tive. blade area. l 'B]Bypoint of symmetry is meant a point which bisects all the line segments through it which arebounded by the generating curve. The point of symmetry for the circle: bisects-all its diameters... See Figure 7 fora curve :which is .notaa-circle, but which'has a point of symmetry. Not all closed curves have points-of symmetry.

The: motor shownin Figure 5 would of course require an indefinitely large number of chambers and blades. in order to run continually, but-if a=section of .iticontaining N+l complete chambers and N' blades is cut out and wrapped around a-cylinder in such a manner that the section of c-axis cut off forms thecircumference of the cylinder (so that the nth and the (rr+N)th blades coin= cide), a continually running: motor results: Figures 1, 2, showthe result for N==41 The .principleof operation wouldbe thesame for N=6, a motor. having six blades and seven chambers with six-distinct'phases; orfor N 7,- a motor having seven-blades. and eight chambers with seven distinct phases; for N:=8; etc; The particular requirements to be put on the motor would determinethe number. of bladesand; chambers used. A motor might alsov be constructed for- Which-the number of blades and chambers would be well in excess of the number'of phases- N by cutting oflE severalrepeating segments of a figure such asFiguIeS. In;this-'casethe-total number of chambers in the rotor would exceed the total number ofblades in the stator by a number equaLto-thenumber of complete phase sets employed in the motor. Obviously the particular requirements of the motor would determine thenumber of. blades and chambers:to. be used. How ever, .it is desirable to keep the number ofblades rather small .soas to .reduce friction andv to give ample room for the blades. and the inlet and outletcircuits. Iris-believed that the optimum numberof blades :formost uses should 20, introducing pressure in the;chambersi 60' resulting in driving. therotor; and fluid inthe chambers; 60.forward:.

Causing the four pointstcrtravel.

is -.evenly-di-visible-by N, andthat it will of the blades is displaced from the chambers into the nozzles 44 thence through the radial passages 42, the annular passage 28, the discharge passage 38 and discharge port 40, thus completing the cycle.

While I have shown and described a preferred embodimerit of my invention, I wish it to Ib understood that I do not confine myself to the precise details of construction herein set forth by way of illustration, as it is ap parent that many changes and variations may be made therein by those skilled in the art, without departing from the spirit of the invention or exceeding the scope of the appended claims.

Having thus described :the invention, what I claim as new and desire to secure by Letters Patent is:

1. A hydraulic power converter comprising a stator [including a cylindrical body having] member and a cooperating rotor member, one of which is provided with equi-spaced radially disposed slots, blades reciprocal in the slots, [a rotor cooperating with said stator and including a ring] the other of said members having a channel contoured to provide sine or cosine cam surfaces constituting chambers for the reception of the blades, there being N+1 chambers for every N blades, [mean-s urging the blades radially outward] said blades being adapted to be urged against said cam surface, means for delivery of all of the fluid supplied to any chamber back of the respective blades and means lfOI' discharge of all of the fluid in each chamber immediately forward of the respective blades, [the variation in spacing of] said [rotor and stator] surfaces being [such] so related that the sum of the exposed areas .of all the [slidable] blades in said chambers remains substantially constant during rotation of said rotor.

2. A hydraulic power converter comprising a fixed support, a stator thereon, sets of equi-spaced blades in the stator, means urging the blades in one direction of movement, a :rotor receiving the stator, chambers in the rotor consisting of successive sine or cosine cam surfaces, the number of chambers coacting with each set of blades exceeding the number of blades of said set by one the arrangement of blades and surfaces being such that the sum of exposed areas of all the blades in said chambers remains substantially constant during rotation of said power converter, and a hydraulic fluid circuit in the stator for flow of fluid to and from the chambers consisting of respective inlet and outlet apertures immediately adjacent to and on opposite sides of the respective Iblzades, an inlet manifold, an outlet manifold, and unobstructed valve-free passages from the respective said inlet and outlet apertures to the respective inlet and outlet manifolds.

3. A hydraulic power converter comprising a stator member and a rotor member, the relation of one to the other being such as to provide contiguous chambers, a plurality of equi-spaced vanes slidably mounted in one of said [stator] members and movable between the stator and the rotor to partition and 'seal the chambers, the relationship .of the vanes to the chambers being such as to present :a constant total active vane area, a fluid inlet on one side of and adjacent each vane and a fluid outlet on the other side of each vane, fluid inlet and outlet passages leading to said inlets and outlets respectively, said fluid inlet and outlet passages being entirely free during normal operation.-

4. A hydraulic fluid power converter having a stator and a rotor concentric therewith, said stator having a surface of revolution and said rotor having a coacting surface opposed to said surface of revolution, said coacting surface being contiguous to said surface of revolution at a number of equally spaced first points and spaced -firom said surface of revolution at gradually in creasing distances intermediate said points to a maximum distance between said points, side walls to define with said surfaces a series of chambers corresponding in number to the number of said spaced points, a series of slots being N+1 chambers in said stator, a blade in each said stator slot slidably biased toward said rotor and extending :between said side walls into contact with said coacting surface of said rotor to divide each said chamber into fluid-tight sections, there being N blades for every N+l chambers, fluid inlet and outlet means for said chambers consisting entirely of a fluid inlet passage in said stator adjacent each blade on one side thereof and a fluid outlet passage adjacent each blade on the other side thereof from the inlet passage, the variation in spacing of said rotor and stator surfaces being such that the sum of exposed areas of all the slidable blades in said chambers remains substantially constant during rotation of said rotor.

5. A hydraulic fluid power converter having a stator member and a rotor member concentric therewith, [said stator] one of said members having a surface of revolution and [said rotor] the other of said members having a coacting surface opposed to said surface of revolution, said coating surface being contiguous to said surface of revolution at a number of equally spaced first points and spaced from said surface of revolution at gradually increasingdistances intermediate said points to a maximum distance between said points, side walls to define with said surfaces a series of chambers corresponding in num her to the number of said spaced points, a series of slots in [said stator] the member having a surface of revolution, a blade in each said [stator] slot [slidably] adapted to be biased toward the other said [rotor] member and extending between said side walls into contact with said coacting surface [of said rotor] to divide each said chamber into fluid-tight sections, the number of blades being less than the number of chambers, fluid inlet and outlet means for said chambers consisting entirely of a fluid inlet passage in [said stator] the slotted member adjacent each slide on one side thereof and a fluid outlet passage adjacent each slide on the other side thereof from the inlet passage, the variation in spacing of said coacting rotor and stator surfaces being such that the sum of exposed areas of all .the slidable blades in said chambers remains substantially constant during rotation of said rotor said inlet and outlet passages terminating on the stator surface in slots extending substantially completely between said side walls].

6. The invention according to claim 5, said inlet and outlet passages extending respectively from [said slots] the surface of said slotted member into respective inlet and outlet manifolds in said [stator] slotted member.

7. The invention according to claim [4] 5, said chambers being identical and the cross sectional area of each such chamber varying symmetrically from zero at said equally spaced points to a maximum between said points as a sine function.

8. A hydraulic fluid power converter having a stator member and a rotor member, one of which has a surface of revolution and the other of which has a coacting surface opposed to said surface of revolution, said coacting surface being contiguous to said surface of revolution at a number of equally spaced points and being spaced from said surface of revolution at gradually increasing distances which vary with the angle of revolution according to a mathematical function to a maximum distance between said points, side walls to define with said surfaces a series of chambers corresponding in number to the number of said spaced points, the member having a surface of revolution containing a series of slots, a blade in each said slot slidably biased toward the other said member and extending between said side Walls into contact with the coacting surface of said other member to divide each said chamber into fluid-tight sections, there for every N blades, fluid inlet and outlet means for said chambers consisting entirely of a fluid inlet passage adjacent each blade on one side thereof and a fluid outlet passage adjacent each blade on the other side thereof from the inlet passage, the variation in spacing of such coacting surfaces being such that the sum of the exposed areas of all the-slidablepblades. in said chambers remains substantially constant during rotation of said rotor.

References Cited in the fil'e of this patentor the original patent UNITED STATES-'PATEN I- ST 385,805 Gregerseu-etal; Jilly 10, 1888 8 Dtzaring Dec-.6, 1.898 Dl'earing Feb. 11 19.02.. Jungarsent et -al.' Nov.v7, 1905' Cbttrell July-9, 1907 Calkins Oct. 22', 1907 Williams May 5; 1925 G'reubel Feb. 10, 1948 

